How Do I Choose The Right Mattress Size?

UK Mattress Size Guide (2024)

Last updated: 31.10.2023 Reading time: 14 Min.

Did you know that humans spend about a third of their life sleeping? 😲

That's a lot of time spent in bed!

It makes sense, then, that your mattress should be comfortable - and that it's big enough to meet all your requirements! 😍

So, what is the perfect mattress size?

And how do you begin to choose the best size to fit your needs?

We'll answer these questions - and more - in our mattress sizes UK guide below. 🇬🇧

Let's get started!

Mattress sizes

Standard UK mattress sizes

Before we even begin helping you decide what size mattress you need, let's start off with a quick overview of what mattress sizes are available.

Different countries have different mattress sizes. 😳

If you've come from Europe or America, take a look at our guide to European mattress sizes and US mattress sizes in the FAQ section of this article.

Here is an overview of the standard UK mattress sizes, looking at bed sizes in cm and inches:

Metric dimensions W x L (cm) Imperial dimensions W x L (feet)
Cot 60 x 120 1'9" x 3'9"
Toddler 70 x 140 2'3" x 4'6"
Small single 75 x 190 2'6" x 6'3"
Single 90 x 190 3'0" x 6'3"
Small double 120 x 190 4'0" x 6'3"
Double 135 x 190 4'6" x 6'3"
King 150 x 200 5'0" x 6'6"
Super king 180 x 200 6'0" x 6'6"
Emperor 200 x 200 6'6" x 6'6"

Most UK retailers will only stock UK mattress sizes, though some brands will also have European mattress size options available.

Simba Sleep, for example, sells its acclaimed Simba Hybrid mattress in a variety of UK sizes but also offers European single, European double, and European queen size options.


IKEA mattresses are also more readily available in Euro sizes.

Mattress Sizes uk with measurements

Let's take a closer look at the different UK mattress sizes.

UK cot mattresses

cot mattress size uk

The standard UK cot mattress has dimensions of 60 x 120 cm (1'9" x 3'9").

Cot mattress
Dimensions (W x L): 60 x 120 cm (1'9" x 3'9")
Best suited to: Cot bed frames, babies under the age of 2

These mattresses have been exclusively designed to fit cot beds and are meant for use by babies under the age of 2. 👶

We're big fans of more natural cot mattresses, like the Little Green Sheep Natural Twist mattress.


We don't cover cot mattresses at length in this article but feel free to head over to our guide on cot mattresses and beds for more information.

UK toddler mattresses

toddler mattress size uk

The standard UK toddler mattress has dimensions of 70 x 140 cm (2'3" x 4'6").

Toddler mattress
Dimensions (W x L): 70 x 140 cm (2'3" x 4'6")
Best suited to: Toddlers and small children aged 2 - 6

Toddler mattresses are one size up from cot mattresses. 🧒

They are intended to be used by toddlers and small children between the ages of 2 and 6.

Some mattresses, like the Mamas & Papas Premium Pocket Spring mattress, have dual sides for use by both babies and toddlers.


After age 6, most children are able to move on to adult small single or single-sized mattresses. 🙌

UK small single mattresses

small single mattress size uk

The standard UK small single mattress has dimensions of 75 x 190 cm (2'6" x 6'3").

Small single mattress
Dimensions (W x L): 75 x 190 cm (2'6" x 6'3")
Best suited to: Children, narrow bed frames, guest beds

Small single beds have been designed to fit narrower kids' bed frames. 🛏

They're also a great save-spacing option for spare rooms, though this isn't the most comfortable size for adults.

UK single mattresses

single mattress uk

The standard UK single mattress has dimensions of 90 x 190 cm (3’ x 6’3”).

Single mattress
Dimensions (W x L): 90 x 190 cm (3’ x 6’3”)
Best suited to: Children, teenagers, young adults, small bedrooms

This is a common size in children's bedrooms, but it also works well for teenagers, students, or in very small bedrooms. 👩‍🎓

You'll find this as one of the most common student mattress sizes - some universities actually insist on single beds as the standard student mattress size to discourage overnight guests!

We wouldn't recommend a standard single mattress size UK as a long-term comfort choice for adults.

That said, many couples choose to combine two single mattresses to form one large bed. 👩‍❤️‍👨

This results in a super-king-size bed, though it'd be a tad shorter than the standard super king-size bed dimensions UK - 180 x 190 cm versus 180 x 200 cm.

Unless, of course, you opt for an EU mattress size, where even the single size has a length of 200 cm.

Your best bet would be getting a super king bed frame for the two singles.

Combining two single mattresses ensures that both partners have enough space to move comfortably and also allows for different firmness requirements to be met.

Single mattresses combined
Two single mattresses can be combined to form one larger bed.

We'd highly recommend doing this for partners with a weight difference of 15 kg (33 lbs) or more or for partners with different firmness preferences.

There will be a slight gap between the two mattresses, which can be filled in with a bed bridge.

Alternatively, opting for a zip-and-link mattress like those sold by Dreams, where two mattresses can be zipped together, is a good option.

UK small double mattresses

small double mattress size uk

The standard UK small double mattress has dimensions of 120 x 190 cm (4' x 6'3").

Small double mattress
Dimensions (W x L): 120 x 190 cm (4' x 6'3")
Best suited to: Teenagers, students, young adults with limited bedroom size

A small double mattress is a good option that falls between standard single and standard double mattresses.

These beds are a popular choice for teenagers, students, or young adults who often have budget and space constraints. 💸

Some of the best budget mattresses, like the Simba Essential, are available in small double options.


Small double beds are also convenient for guest bedrooms.

UK double mattresses

double mattress uk

The standard UK double mattress has dimensions of 135 x 190 cm (4’6" x 6’3”).

Double mattress
Dimensions (W x L): 135 x 190 cm (4’6" x 6’3”)
Best suited to: Women, single adults, couples with limited bedroom space

This is the most popular mattress for adults in the UK and will fit an average-sized bedroom.

It's a great option for singles wanting a bit more sleeping space and couples with smaller bedrooms.

The Emma Original is a fantastic double mattress for a great night's sleep.


That said, we wouldn't recommend a UK double mattress size to couples in the long term.

We'll elaborate on this in more detail further down. 👇

Since mattresses should be at least 10 cm longer than the tallest person using the bed, we also wouldn't recommend double mattresses to anyone taller than 180 cm (6'0").

UK king mattresses

king mattress size uk

The standard UK king mattress has dimensions of 150 x 200 cm (5’ x 6’6”).

King mattress
Dimensions (W x L): 150 x 200 cm (5’ x 6’6”)
Best suited to: People taller than 180 cm, single adults, couples

The king-size mattress is our preferred choice for couples. 👑

It offers enough space for two people to sleep comfortably.

But, it's also longer than average and better suited to people taller than 180 cm (6'0").

A mattress like the Nectar mattress, with good support and excellent motion isolation, is a fantastic king-size mattress choice for couples.


And since these bed-in-a-box mattresses are delivered rolled up, you won't have to worry about carrying a massive mattress into your bedroom. 😅

Single adults who like a lot of space or those sharing their bed with a young child or pet will also really enjoy the size of a king bed. 🐈

UK super king mattresses

super king mattress size uk

The standard UK super-king-size mattress has dimensions of 180 x 200 cm (6’ x 6’6”).

Super-king mattress
Dimensions (W x L): 180 x 200 cm (6’ x 6’6”)
Best suited to: Couples, families, people of larger builds or heavier weights

The super king mattress is the premium choice for couples.

It ensures that both partners have more than enough space to sleep comfortably without worrying that they'll disturb each other.

Super-king mattresses are also a good choice for people (and couples) of larger builds or heavier weights, or those with kids or pets that frequently hop into bed with them.

The Simba Hybrid is one of our top choices, offering premium comfort and support.


Unfortunately, super-king mattresses won't fit everyone's budget or bedroom size - but, with bed-in-a-box mattresses, you at least don't have to worry about carrying the mattress into your room.

This is because bed-in-a-box beds are delivered vacuum-packed and rolled up in a cardboard box that's pretty easy to manoeuvre through tighter spaces.

UK emperor mattresses

emperor mattress size uk

The standard UK emperor mattress measures 200 x 200 cm (6’6” x 6’6”).

Emperor mattress
Dimensions (W x L): 200 x 200 cm (6’6” x 6’6”)
Best suited to: Luxury rooms, families, hotel suites

The emperor bed is the largest mattress size available in the UK.

It is a luxurious choice that offers more than enough space and can be used quite comfortably by three people or more (parents, children, and pets). 🙍‍♂️🙍‍♀️🧒🐶

Emperor beds may be the largest standard size but they are not commonly available as bed-in-a-box mattresses.

The only bed-in-a-box brand that we know of that sells emperor beds is Otty.


You'll be more likely to find emperor-sized mattresses at traditional retailers. 🛒

How do you choose the right mattress size?

You may have a vague idea about the size of mattress you need.

But actually deciding while you're hunting for a new mattress can be a little more complicated. 🤯

There is no right mattress size.

Instead, the right mattress size for you depends on a variety of factors, including your height and body weight, the size of your bedroom or studio apartment, and your family setup.

The below questions can guide you:

  • Are you short, tall, or of average height?
  • Are you light-weight, of average weight, or slightly heavier?
  • Do you sleep alone or do you share your bed with a partner?
  • Do you have children or pets that share your bed with you?
  • Are you a restless sleeper?
  • If you have a partner, is your partner a restless sleeper?
  • How big is your bedroom?
  • How big/wide are your staircases, entryways, and corridors?

These questions may not give you a definitive answer, but they will help put you on the right path. ✅

Woman thinking
Asking a few key questions can help you figure out which mattress size is best.

It's also worth noting that bed-in-a-box brands give you the opportunity to try larger beds that traditionally wouldn't have fit through entryways or corridors.

This is very convenient for people with narrow staircases or those living in loft apartments where a larger bed may fit, but carrying it up would have been an issue otherwise.

You can also consider the following:

  • If you're buying a replacement mattress, measure your current bed frame and bedding dimensions, and buy a mattress in the same size.
  • If you're buying a bed & mattress for the first time or you want to upgrade your bedroom setup, consider your budget (also include costs of the bed frame and bedding) and the size of your bedroom, and choose from there.

These factors can act as a guideline to help you choose your new bed.

Don't forget to always consider the space around your bed as well - i.e. you'll still need space for bedside tables and ensure that the bed doesn't block any doors, windows, or power outlets.

Bed frame
You need to consider the overall size of your bedroom.

If you're looking to buy a bed and mattress, it may be worth looking into a bundle deal.

These combine a bed frame with a mattress and fitting sleep accessories. 🛌

These are some of our favourite bundle deals:

How wide should your mattress be?

If you're sleeping by yourself, the width of your mattress doesn't really matter too much. 🤔

You'd be able to sleep comfortably on most adult mattresses.

Of course, if you're a very restless sleeper and frequently toss and turn at night, a slightly wider mattress will be more comfortable. 🕺

Width becomes more of an issue, though, if you share your bed with a partner.

The double bed size, available from some of our favourite brands, like Nectar, is the most popular choice for adults in the UK.


Couple snuggling in bed
Double beds can be a bit too narrow for couples.

But, this mattress is only 135 cm (4’6") wide - giving each partner only 67.5 cm (2'3") of space.

That's narrower than a toddler mattress! 😳

Sure, if you're a snuggle bunny and you and your partner love being cosy with little room to move, this isn't a train smash.

But, it also means that you're more likely to disturb your partner every time you change sleep position, eventually resulting in poor sleep. ☹️

This is one of the reasons we always recommend a mattress with good motion isolation, which ensures that movements aren't carried across the mattress.

Man and woman in bed
Body size and build influence how wide your mattress should be.

This becomes even more of an issue if you take build and body size into account.

Here's a simple test to determine if a mattress is large enough for two people:

  • Lie next to your partner on the mattress.
  • Both of you should lie on your backs and put your hands behind your head, with elbows sticking out.
  • If your elbows don't touch, the mattress is big enough and you'll have enough room to sleep comfortably.
  • If your elbows touch, you'll need a bigger mattress.

If you and your partner are both on the smaller side, you wouldn't have much of a problem.

But if you're of average or above-average build, height, or weight, a double mattress will quickly become too small.

This is why we'd always recommend couples opt for a king-size bed or larger. 👑

One of our favourite mattresses for couples is the DreamCloud Luxury Hybrid.

It's large, luxurious, and oh-so-comfortable.


You can also read our full guide on the best mattresses for couples in the UK.

How long should your mattress be?

Your mattress should be at least 10 cm (3.9 inches) longer than the tallest person using the bed.

  • Standard single and double beds only have a length of 190 cm (6'3").
  • Standard king, super king, and emperor beds have a length of 200 cm (6'6").

If you're taller than 180 cm (5'9"), you should ideally opt for a bed with a length of 200 cm. 📏

In the UK, only the king, super king, and emperor mattresses have a length of 200 cm.

European mattresses, in contrast, always have a length of 200 cm, so if you're looking for a longer single or double bed, it'd make sense to opt for a brand like Simba that actually sells both UK and EU mattress sizes.


If you're taller than 190 cm (6'2"), though, it'd be best to invest in an extra-length bed for added comfort.

After all, you don't want your feet sticking out at the end of the bed. 🦶

Taller people should also avoid opting for bed frames with a foot end, as this restricts the amount of space available.
Legs in bed
Your mattress should be 10 - 20 cm longer than you are tall.

How high should your mattress be?

The height or thickness of a mattress does not affect the overall mattress size.

To measure a mattress's size, we only look at the width and length of the mattress.

But, the thickness or height of a mattress affects the overall look and feel of your bed.

Thick mattress
Thicker mattresses tend to be comfortable and last longer.

As a rule of thumb:

The thicker the mattress, the more comfortable and luxurious it will be.

Thicker mattresses also tend to last longer.

Here's a quick guide:

  • For foam mattresses, we recommend a minimum mattress thickness of 18 cm (7 inches).
  • For spring mattresses, we recommend a minimum mattress thickness of 23 cm (9 inches).

Most standard bed-in-a-box mattresses, like the Emma Original, have a height of 25 cm (10 inches).


This is a comfortable thickness that will look nice on any bed frame. 🙃

Conveniently, this standard size is also practical as it ensures most bedding will fit!

But there are a few thinner, lighter options available, like the Eve Lighter mattress.

This mattress only measures 20 cm (7.8 inches).

Thinner mattresses are more budget-friendly and are a great option for children or guest bedrooms.

You may also wish to opt for a thinner mattress if your child or pet shares your bed and you don't want to risk them falling (or jumping) out and hurting themselves.

Dreamcloud luxury hybrid mattress
Luxury mattresses like the DreamCloud Hybrid tend to be thicker.

There are also a few thicker mattress options available, which are higher than the standard 25 cm.

The DreamCloud Luxury Hybrid, for example, has an average height of 28 cm (11 inches).


Thicker mattress for the elderly
Thicker mattresses make getting into and out of bed easier.

Thicker mattresses tend to give bedrooms a more luxurious feel. 🌟

They can also be more convenient for the elderly, as it makes getting in and out of bed easier.

What size should your bed frame be?

Bed sizes UK & mattress sizes UK often go hand-in-hand.

Bed frames are available in a range of different UK bed sizes to match your chosen mattress.

If you choose a super king size mattress size UK, for example, you also need to purchase a super king size bed frame.

The standard bed sizes UK will include:

  • Standard small single bed
  • Standard single bed
  • Standard small double bed
  • Standard double bed
  • Standard king bed
  • Standard super king bed

Some frames aren't available in smaller sizes, so it's always a good idea to check out bed frames and mattresses at the same time.

People measuring bed
Always get accurate measurements to make sure your bed frame will fit into your bedroom.

Will my bed frame fit?

UK bed sizes may come with the same size descriptions as your mattress (such as small, double, or king size bed size UK).

But this does not mean that the bed dimensions will necessarily be the same as the mattress dimensions. 😱

The dimensions of your frame will depend on the style of frame you choose:

  • Divan beds or box springs (without a headboard) will have the same dimensions as your mattress since the mattress simply sits on top of the divan base.
  • Wooden bed frames are usually slightly larger than your mattress, with a few extra centimetres on each side.
  • Upholstered bed frames vary in size, depending on the shape of the frame and fabric used.

Always get accurate measurements of the space available to make sure your desired bed frame will fit and make sure the bed won't block any required power outlets, doors, etc. 📏

Don't forget to take into account the design of the headboard (thicker or curved headboards, like the one on the Simba Orion Bed, take up more space) and whether or not the bed has a foot end.

Beds like the Simba come flat-packed in boxes, so you just need to worry about the space in your room and not how wide your stairways, corridors, or doorways are.

This is super convenient for tight spaces or loft rooms.

Also, keep in mind how much space you'd need for bedside tables or if you need space on both sides of the bed for partners to climb in.

Those with minimal space should opt for a divan base without a headboard.

Some of our favourite UK bed frames:

What's the best mattress size?

As you've seen, there's not one best mattress size.

The right mattress size for you will depend on your budget, sleeping requirements, relationship status, and the size of your bedroom.

While you can opt for a few custom sizes, we'd highly recommend sticking to standard UK mattress sizes.

This makes finding suitable bedding a breeze.

Need some mattress recommendations?

Here are a few of our favourite UK mattresses:

Frequently asked questions

  • What are the standard European mattress sizes?

    The standard European mattress sizes, looking at bed sizes in cm and inches, are:

      Width x Length (cm) Width x Length (inches)
    Euro single  90 x 200 3’0” x 6’6”
    Euro small double 120 x 200 4’0” x 6’6”
    Euro double 140 x 200 4’7” x 6’6
    Euro queen/king 160 x 200 5’3” x 6’6”
    Euro super king 180 x 200 6’0” x 6’6”
    Euro emperor 200 x 200 6'6" x 6'6"

    Some UK retailers will stock European-sized mattresses.

  • What are the standard US mattress sizes?

    The standard American mattress sizes, looking at bed sizes in cm and inches, are:

      Width x Length (cm) Width x Length (inches)
    Twin (single) 98 × 189 3’2” x 6’2”
    Twin XL 98 × 202 3'2" x 6'6"
    Double 136 x 189 4’5” x 6’2”
    Queen 152 x 202 5’0” x 6’6”
    King 193 x 202 6’3” x 6’6”
    California 183 x 212 6’0” x 7’0”

    These are rare to find in the United Kingdom. 

  • How do UK, EU, and US mattress sizes compare?

    Here is a quick overview of how standard British mattress sizes compare with standard European and standard US mattress sizes.

      UK EU US
    Single 90 x 190 cm 90 x 200 cm 98 × 189 cm (Twin)
    Small double 120 x 190 cm 120 x 200 cm  98 × 202 (Twin XL)
    Double 135 x 190 cm 140 x 200 cm 136 x 189 cm
    Queen N/A 160 x 200 cm 152 x 202 cm
    King 150 x 200 cm N/A 193 x 202
    Super king 180 x 200 cm 180 x 200 cm 183 x 212 (California)
  • What is the best mattress size for singles?

    Most people who sleep alone can sleep quite comfortably on the following sizes:

    • Single mattresses sized 90 x 190 cm
    • Small double mattresses sized 120 x 190 cm
    • Double mattresses sized 135 x 190 cm

    We'd suggest opting for the 135 x 190 cm double size.

    This will be more comfortable and give you enough space in case your personal situation changes or you happen to adopt a dog or need more space for Netflix marathons. 📺

    Children and adolescents will also be quite comfortable with these sizes, but may also opt for a small single mattress, depending on the size of their bedroom. 

  • What is the best mattress size for couples?

    We recommend that couples choose one of the following sizes:

    • Double size mattresses 135 x 190 cm
    • King size mattresses 150 x 200 cm
    • Super-king size mattresses 180 x 200 cm

    The double-size mattress would be the minimum as couples wouldn't be able to sleep comfortably on a smaller size.

    But, even then, we'd suggest choosing a UK king size mattress or larger. 

    UK king-size mattresses give you enough space for a comfortable and restful sleep without disturbing your partner.

    If your partner is quite restless or tends to end up lying crosswise, an even slightly larger mattress, like the super-king mattress, would be better.

    If you have pets or children who like to hop into bed with you, then we'd definitely recommend a super-king size mattress or even an emperor bed, provided your bedroom is large enough. 

  • What are extra-length mattresses?

    Some retailers will offer custom mattress sizes.

    These usually include oversized or extra-length mattresses with lengths of 210 cm (6'8") or 220 cm (7'2").

    If you or your partner are very tall (over 2 metres), investing in an oversized or extra-length mattress is a good idea.

    After all, there's nothing worse than your feet sticking out at the end of your bed. 👣

    Your mattress should be at least 10 cm - 20 cm (3.9 - 7.8 inches) longer than you! 

  • What is a queen size bed?

    Other markets, like Europe, the USA, and even South Africa, offer a queen-size bed.

    Measurements according to country differ, but generally, queen-size mattresses range from 152 x 200 cm to 160 x 200 cm.

    In the UK, however, the term "queen-size bed" effectively refers to a small double bed

    The UK queen mattresses measure a mere 120 x 190 cm (3’9” x 6’2”), making them one of the smallest options that's not a single.

    We wouldn't recommend UK queen mattresses to couples, but they would be a comfortable fit for teenagers or young adults just transitioning to larger beds.

    The larger queen-size mattresses, as the term is used elsewhere, are not readily available in the UK. 

    The next-best alternative would be the UK king-size mattress, which measures 150 x 200 cm.

  • Why are UK beds so small?

    On average, UK beds tend to be smaller than their European and American counterparts.

    Why is that?

    One theory is that UK homes [1], on average, are much smaller - and shrinking!

    In order to accommodate smaller bedrooms, beds necessarily have to be smaller.



Editor & Certified Sleep Therapist

Nicky is an experienced writer and editor with numerous qualifications. As a certified sleep coach, her interests lie in understanding how sleep problems arise from hormonal and environmental issues, particularly as part of stress and anxiety management.

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